Shoulder strap system for a backpack



FIG. 1 is a front perspective view of a shoulder strap system for a backpack showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is right side elevation view thereof;

FIG. 6 is a left side elevation view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken line illustration of environmental structure in the drawings is not part of the claimed design. 

CLAIM The ornamental design for a shoulder strap system for a backpack, as shown and described. 